The root ر ه ب (r-h-b) in the Quran

يَٰبَنِىٓ إِسْرَٰٓءِيلَ ٱذْكُرُوا۟ نِعْمَتِىَ ٱلَّتِىٓ أَنْعَمْتُ عَلَيْكُمْ وَأَوْفُوا۟ بِعَهْدِىٓ أُوفِ بِعَهْدِكُمْ وَإِيَّٰىَ فَٱرْهَبُونِ ۝٤٠

O Children of Israel, remember My favor which I have bestowed upon you and fulfill My covenant [upon you] that I will fulfill your covenant [from Me], and be afraid of [only] Me.

لَتَجِدَنَّ أَشَدَّ ٱلنَّاسِ عَدَٰوَةً لِّلَّذِينَ ءَامَنُوا۟ ٱلْيَهُودَ وَٱلَّذِينَ أَشْرَكُوا۟ وَلَتَجِدَنَّ أَقْرَبَهُم مَّوَدَّةً لِّلَّذِينَ ءَامَنُوا۟ ٱلَّذِينَ قَالُوٓا۟ إِنَّا نَصَٰرَىٰ ذَٰلِكَ بِأَنَّ مِنْهُمْ قِسِّيسِينَ وَرُهْبَانًا وَأَنَّهُمْ لَا يَسْتَكْبِرُونَ ۝٨٢

You will surely find the most intense of the people in animosity toward the believers [to be] the Jews and those who associate others with Allāh; and you will find the nearest of them in affection to the believers those who say, "We are Christians." That is because among them are priests and monks and because they are not arrogant.

قَالَ أَلْقُوا۟ فَلَمَّآ أَلْقَوْا۟ سَحَرُوٓا۟ أَعْيُنَ ٱلنَّاسِ وَٱسْتَرْهَبُوهُمْ وَجَآءُو بِسِحْرٍ عَظِيمٍ ۝١١٦

He said, "Throw," and when they threw, they bewitched the eyes of the people and struck terror into them, and they presented a great [feat of] magic.

وَلَمَّا سَكَتَ عَن مُّوسَى ٱلْغَضَبُ أَخَذَ ٱلْأَلْوَاحَ وَفِى نُسْخَتِهَا هُدًى وَرَحْمَةٌ لِّلَّذِينَ هُمْ لِرَبِّهِمْ يَرْهَبُونَ ۝١٥٤

And when the anger subsided in Moses, he took up the tablets; and in their inscription was guidance and mercy for those who are fearful of their Lord.

وَأَعِدُّوا۟ لَهُم مَّا ٱسْتَطَعْتُم مِّن قُوَّةٍ وَمِن رِّبَاطِ ٱلْخَيْلِ تُرْهِبُونَ بِهِۦ عَدُوَّ ٱللَّهِ وَعَدُوَّكُمْ وَءَاخَرِينَ مِن دُونِهِمْ لَا تَعْلَمُونَهُمُ ٱللَّهُ يَعْلَمُهُمْ وَمَا تُنفِقُوا۟ مِن شَىْءٍ فِى سَبِيلِ ٱللَّهِ يُوَفَّ إِلَيْكُمْ وَأَنتُمْ لَا تُظْلَمُونَ ۝٦٠

And prepare against them whatever you are able of power and of steeds of war by which you may terrify the enemy of Allāh and your enemy and others besides them whom you do not know [but] whom Allāh knows. And whatever you spend in the cause of Allāh will be fully repaid to you, and you will not be wronged.

ٱتَّخَذُوٓا۟ أَحْبَارَهُمْ وَرُهْبَٰنَهُمْ أَرْبَابًا مِّن دُونِ ٱللَّهِ وَٱلْمَسِيحَ ٱبْنَ مَرْيَمَ وَمَآ أُمِرُوٓا۟ إِلَّا لِيَعْبُدُوٓا۟ إِلَٰهًا وَٰحِدًا لَّآ إِلَٰهَ إِلَّا هُوَ سُبْحَٰنَهُۥ عَمَّا يُشْرِكُونَ ۝٣١

They have taken their scholars and monks as lords besides Allāh, and [also] the Messiah, the son of Mary. And they were not commanded except to worship one God; there is no deity except Him. Exalted is He above whatever they associate with Him.

يَٰٓأَيُّهَا ٱلَّذِينَ ءَامَنُوٓا۟ إِنَّ كَثِيرًا مِّنَ ٱلْأَحْبَارِ وَٱلرُّهْبَانِ لَيَأْكُلُونَ أَمْوَٰلَ ٱلنَّاسِ بِٱلْبَٰطِلِ وَيَصُدُّونَ عَن سَبِيلِ ٱللَّهِ وَٱلَّذِينَ يَكْنِزُونَ ٱلذَّهَبَ وَٱلْفِضَّةَ وَلَا يُنفِقُونَهَا فِى سَبِيلِ ٱللَّهِ فَبَشِّرْهُم بِعَذَابٍ أَلِيمٍ ۝٣٤

O you who have believed, indeed many of the scholars and the monks devour the wealth of people unjustly and avert [them] from the way of Allāh. And those who hoard gold and silver and spend it not in the way of Allāh - give them tidings of a painful punishment.

وَقَالَ ٱللَّهُ لَا تَتَّخِذُوٓا۟ إِلَٰهَيْنِ ٱثْنَيْنِ إِنَّمَا هُوَ إِلَٰهٌ وَٰحِدٌ فَإِيَّٰىَ فَٱرْهَبُونِ ۝٥١

And Allāh has said, "Do not take for yourselves two deities. He [i.e., Allāh] is but one God, so fear only Me."

فَٱسْتَجَبْنَا لَهُۥ وَوَهَبْنَا لَهُۥ يَحْيَىٰ وَأَصْلَحْنَا لَهُۥ زَوْجَهُۥٓ إِنَّهُمْ كَانُوا۟ يُسَٰرِعُونَ فِى ٱلْخَيْرَٰتِ وَيَدْعُونَنَا رَغَبًا وَرَهَبًا وَكَانُوا۟ لَنَا خَٰشِعِينَ ۝٩٠

So We responded to him, and We gave to him John, and amended for him his wife. Indeed, they used to hasten to good deeds and supplicate Us in hope and fear, and they were to Us humbly submissive.

ٱسْلُكْ يَدَكَ فِى جَيْبِكَ تَخْرُجْ بَيْضَآءَ مِنْ غَيْرِ سُوٓءٍ وَٱضْمُمْ إِلَيْكَ جَنَاحَكَ مِنَ ٱلرَّهْبِ فَذَٰنِكَ بُرْهَٰنَانِ مِن رَّبِّكَ إِلَىٰ فِرْعَوْنَ وَمَلَإِي۟هِۦٓ إِنَّهُمْ كَانُوا۟ قَوْمًا فَٰسِقِينَ ۝٣٢

Insert your hand into the opening of your garment; it will come out white, without disease. And draw in your arm close to you [as prevention] from fear, for those are two proofs from your Lord to Pharaoh and his establishment. Indeed, they have been a people defiantly disobedient."

ثُمَّ قَفَّيْنَا عَلَىٰٓ ءَاثَٰرِهِم بِرُسُلِنَا وَقَفَّيْنَا بِعِيسَى ٱبْنِ مَرْيَمَ وَءَاتَيْنَٰهُ ٱلْإِنجِيلَ وَجَعَلْنَا فِى قُلُوبِ ٱلَّذِينَ ٱتَّبَعُوهُ رَأْفَةً وَرَحْمَةً وَرَهْبَانِيَّةً ٱبْتَدَعُوهَا مَا كَتَبْنَٰهَا عَلَيْهِمْ إِلَّا ٱبْتِغَآءَ رِضْوَٰنِ ٱللَّهِ فَمَا رَعَوْهَا حَقَّ رِعَايَتِهَا فَـَٔاتَيْنَا ٱلَّذِينَ ءَامَنُوا۟ مِنْهُمْ أَجْرَهُمْ وَكَثِيرٌ مِّنْهُمْ فَٰسِقُونَ ۝٢٧

Then We sent following their footsteps [i.e., traditions] Our messengers and followed [them] with Jesus, the son of Mary, and gave him the Gospel. And We placed in the hearts of those who followed him compassion and mercy and monasticism, which they innovated; We did not prescribe it for them except [that they did so] seeking the approval of Allāh. But they did not observe it with due observance. So We gave the ones who believed among them their reward, but many of them are defiantly disobedient.

لَأَنتُمْ أَشَدُّ رَهْبَةً فِى صُدُورِهِم مِّنَ ٱللَّهِ ذَٰلِكَ بِأَنَّهُمْ قَوْمٌ لَّا يَفْقَهُونَ ۝١٣

You [believers] are more fearful within their breasts than Allāh. That is because they are a people who do not understand.